JPH0623569Y2 - Plasma generation reactor - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention, in the fields of electronics, chemical industry, etc., uses plasma CVD to generate plasma for generating diamond, nitride film, etc. on a fixed surface (substrate), etc. The present invention relates to a reactor, and more particularly to a plasma generation reactor having a single microwave oscillator and a plurality of applicators.

[Prior Art] Conventionally, as a plasma generation reaction device of this type, there is one shown in FIG. 5, for example. The microwave oscillated by the microwave oscillator 1 passes through the isolator 2 and reaches the applicator 3 as a plasma generator. Reference numeral 4 is an absorber for absorbing reflected waves, 5 is a power monitor for measuring incident power and reflected power, and 6 is a three-stub tuner for impedance matching. Quartz pipe 7 in the applicator 3
Is inserted, and the reaction gas and the carrier gas are introduced into the quartz pipe 7 through the gas introduction pipe 8.
A rotatable sample table 9 is provided at a supporting portion of the gas supply system and the microwave system, and a sample 10 on which a thin film or the like is to be formed is placed on the sample table 9. Reference numeral 11 is a variable short-circuiter that generates a standing wave at its crossing part. 12 is an exhaust pipe, 13
Is a vacuum gauge.

[Problems to be Solved by the Invention] However, in the above plasma generation reaction device,
There are the following problems.

The variable short-circuit device 11 is operated so that the maximum point of the standing wave exists inside the depressurized quartz pipe 7, and the slush tub tuner 6 is adjusted to generate plasma. Including the time required for operations before and after that (preparation of sample, depressurizing operation, cooling of sample after experiment, etc.), one experiment requires at least 6 to 7 hours. Therefore, a long-term experiment was inevitable until various data were obtained with different experimental conditions such as mixing ratio of various gases, vacuum degree, and microwave power.

In order to avoid the above-mentioned long-term experiment, a plurality of plasma generating reactors may be used, but this causes an increase in experimental space and cost.

The present invention solves the above problems, and an object of the present invention is to save the experimental space and suppress the cost increase, and to generate a plurality of thin films at a time under various experimental conditions. To provide.

[Means for Solving the Problems] In order to achieve the above object, in the plasma generation reaction device according to the present invention, only a single microwave oscillator that generates microwaves is used, and the microwaves are introduced. A distribution circuit that distributes microwaves of predetermined power is provided to a plurality of branch systems including applicators.

[Operation] According to the plasma generation reaction device having such a configuration, the microwave generated by the single microwave oscillator is supplied to the distribution circuit, but the introduced microwave is distributed from the distribution circuit to the plurality of branch systems. After that, since each applicator is supplied, plasma generation for each applicator is realized.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of a plasma generation reaction device according to the present invention. The plasma generation reactor is
A microwave oscillator 20 such as a magnetron, a distribution circuit 30, and a plurality of branch systems A to E are roughly configured. An isolator 25 is interposed between the microwave oscillator 20 and the distribution circuit 30, which removes a reflected wave from the distribution circuit 30,
It is intended to stabilize the oscillation characteristics of the microwave oscillator 20.

As shown in FIG. 2, the distribution circuit 30 includes a rectangular main pipe 31 having an inlet 31a and a terminal end 31b, and branch pipes 32 to 36 connected to the E surface (electric field surface) of the rectangular main pipe 31 at regular intervals. It is configured. Microwaves are distributed from the main pipe 31 to the branch pipes 32 to 36 through the slots 32a to 36a formed on the E surface. In this embodiment, the slots 32a to 36a have the same shape, the same angle, and the like, and the distributed microwave power is substantially equal. Here, as shown in FIG.
When the width of 31 is a, the height is b, the angles of the slots 32a to 36a are θ, and the slot length is λ0 / 2, the branching portion is shown in FIG. 3 (C).
With an equivalent circuit as shown in, its conductance G is λ: given in tube wavelength The conductance G changes by changing each angle θ. For example, when G = 1/5, the slot interval is set to λ0 / 2, and by providing five slots, the main pipe 31 and the branch pipes 32 to 36 can be matched, and the microwave power is 1 / 5 is distributed.

Each of the branching systems A to E turns on / off the isolator 41 that absorbs the reflected wave of the distributed microwave and the supply of the distributed microwave.
The F cutoff circuit 42, the power control stub 43 that adjusts the supplied microwave power, the power monitor 44 that measures the incident power and the reflected power, the three-stub tuner 45 that achieves impedance matching, and the plasma generator It is composed of an applicator 46 and a variable short circuiter 47 for adjusting the standing wave position in the applicator 46.

As shown in FIG. 4, the cutoff circuit 42 includes a shutter plate 42d that can be inserted into and removed from the gap 42c between the abutted rectangular waveguides 42a and 42b, and a slide plate that facilitates the sliding movement of the shutter plate 42d. It is composed of block halves 42e and 42f. The shutter plate 42d is formed with a plate thickness portion 42g having a length of 1 at the front end portion thereof. The shutter plate 42d is prevented from coming off, and when it is completely opened, the front end surface of the plate thickness portion 42g and the waveguide are guided. Microwave leakage preventing quarter-chokes 42h and 42i are formed at positions where the inner surfaces of the tubes 42a and 42b are aligned with each other.

Next, the function and effect of the above embodiment will be described. The microwave generated by the single microwave oscillator 20 is supplied to the distribution circuit 30. Here, the reflected wave of the supplied microwave is the isolator
Since it is absorbed by 25, stable oscillation of the microwave oscillator 20 is performed. The microwave introduced into the distribution circuit 30 is equally divided and a plurality of branch systems A to
Supplied to E. In each of the branching systems A to E, the cutoff circuit 42 is used to adjust the microwave supply power to the applicator 46.
And the power control stub 43. The ON / OFF adjustment of the microwave supply can be performed by opening / closing the shutter plate 42d of the cutoff circuit 42. When completely opened, the front end surface of the plate thickness portion 42g and the inner surfaces of the waveguides 42a and 42b coincide with each other, so that the shutter plate 42d does not affect microwaves. Also, the microwave power can be adjusted in an analog manner by changing the aperture width. Shutter plate here
Since the reflected wave of 42d is absorbed by the isolator 41, it does not affect the distribution circuit 30 depending on the opening / closing degree of a particular shutter plate, and prevents fluctuations in the distribution power value to other branch systems. As the opening width of the cutoff circuit 42 becomes closer to the microwave cutoff region, it becomes difficult to control the power, but in this embodiment, since the power control stub 43 is provided after the cutoff circuit 42, the opening width is reduced. By adjusting the power control stub 43 by changing it outside the microwave cutoff range, analog adjustment for the applicator 46 that maximizes the distributed power value introduced into the branch system is realized. Of course, it is also possible to completely open the shutter plate 42d and adjust only the power control stub 43.

The microwaves supplied to each applicator 46 generate plasma in the applicator 46 to generate diamond, a nitride film, and the like. In this embodiment, five branch systems A to
Since E is provided, it is possible to perform 5 types of experiments at the same time. In particular, since the condition setting is independent by providing the isolator 41 for each system after the distribution circuit 30, it corresponds to the case of using the conventional five plasma generation reaction devices. Moreover, it is possible to save the device space and reduce the device cost as compared with the conventional one.

[Effects of the Invention] As described above, the plasma generation reaction device according to the present invention includes a single microwave oscillator for generating microwaves and a plurality of branching systems including applicators for introducing the microwaves. On the other hand, since it is characterized in that it has a distribution circuit that distributes microwaves of a predetermined power, it has the following effects.

It is possible to operate multiple applicators by adjusting the operation of one microwave oscillator.
It is possible to simultaneously perform an experiment for forming a nitride film or the like, which facilitates the experiment work and shortens the experiment time.

As compared with the case where a plurality of conventional devices are used, the experimental space can be saved and the cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a plasma generation reaction device according to the present invention. FIG. 2 (A) is a cross-sectional view of the distribution circuit in the embodiment,
FIG. 2B is a vertical sectional view of the distribution circuit. FIG. 3 (A) is a schematic view showing slots of the distribution circuit,
Figure (B) is a diagram showing the dimensional relationship of the mains of the distribution circuit.
FIG. (C) is an equivalent circuit diagram of the slot portion. FIG. 4 (A) is a cross-sectional view of the breaking circuit in the same embodiment, and FIG. 4 (B) is a side view of the breaking circuit. FIG. 5 is a block diagram showing an example of a conventional plasma generation reaction device. [Explanation of main symbols] 20 …… Microwave oscillator, 25, 41 …… Isolator, 30
...... Distribution circuit, 31 …… Main pipe, 32 to 36 …… Branch pipe, 32a to 3
6a …… slot, AE …… branching system, 42 …… break circuit,
42d ... Shutter plate, 42h, 42 ... 1/4 choke, 43 ...
… Power control stubs, 44… Power monitors,
45 …… Three-stub tuner, 46 …… Applicator, 47
...... Variable short circuiter.

Claims (1)

[Scope of utility model registration request] 1. A device for generating plasma in an applicator by a microwave to generate a thin film, a crystal or the like on an object surface, and a single microwave oscillator for generating the microwave and introducing the microwave. And a distribution circuit that distributes microwaves of a predetermined power to a plurality of branch systems equipped with applicators.